Perhaps this problem is not common in your area, but here and in many urban/suburban settings in California, there is a huge problem with delivered packages being stolen from doorways and porches.
In many cases, thieve(s) simply follow delivery trucks (UPS, FedEx, USPS) and pluck packages shortly after delivery. But it seems to me that there is a simple mechanism that would limit the other, more-common cases of trolling neighborhoods for left packages.
What if everybody left a dummy package outside their door? For example, a simple box with a bogus label and weighty contents would do the trick; ideally, a box with retail branding (such as Amazon or others with recognizable logo). (I am not suggesting anything toxic or dangerous, just worthless stuff that provides an appropriate look and feel.)
Am I missing something? If such a simple countermeasure was widely practiced, the sheer risk ratio could at least provide a low-cost deterrent.
Obviously, the better solution would be bait packages with tracking devices that would alert law enforcement when moved and serve as probable cause for searches... but in my area, at least, property crime generally gets no attention from law enforcement.